JPH0552604U - Microwave oven with heater - Google Patents

Abstract

(57) [Abstract] [Purpose] In a microwave oven with a heater provided with a plate-shaped heater, the thermal efficiency is improved and the temperature rise of a box forming a cooking chamber is suppressed. [Structure] Bottom plate portion 14 of inner box 14 constituting cooking chamber 13
The recess 19 is formed in b. The flat-plate heater 22 is covered with a stainless steel case 23 in a state where its peripheral portion is hermetically sealed to form the heater unit 17. The heater unit 17 is housed in the recess 19 so as to be flush with the bottom of the cooking chamber 13. At this time, the curl portion of the outer peripheral edge portion of the heater unit 17 and the inner peripheral edge portion of the recess 19 are brought into contact with each other without a gap, and a gap is provided between the heater unit 17 and the bottom plate portion 14b.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a heater-equipped electronic range capable of performing heating and cooking with a flat heater.

[0002]

[Prior Art]

 Some microwave ovens are capable of heating and cooking by heating with a heater in addition to microwave heating. As shown in FIG. 7, an inner box 3 which constitutes a cooking chamber 2 is provided in a main body 1, and the inner box 3 has an inner box 3 on an upper surface side of a top plate portion 3a and a lower surface side of a bottom plate portion 3b, respectively. A flat plate heater 4 is provided. As shown in FIG. 8, the flat plate-shaped heater 4 is constructed by sandwiching a thin core mica 5 around which a heater wire 6 is wound from above and below by two thin cover mica 7, 7. The holding plate 8 was attached so as to be in close contact with the outer surface of the inner box 3 (top plate portion 3a).

[0003]

[Problems to be solved by the device]

 However, the above-mentioned conventional structure has the following drawbacks. That is, since the heat of the flat plate-shaped heater 4 is first transferred to the inner box 3, and the heat of the inner box 3 heats the inside of the cooking chamber 2, the heat of the inner box 3 is dissipated to the outside of the cooking chamber 2. In many cases, the heat efficiency was poor.

Further, since the temperature of the entire inner box 3 rises to a high temperature, it is easy to adversely affect electrical components and plastic members arranged outside the inner box 3, and therefore heat shielding, heat insulation, etc. It was necessary to take measures for the above, and there was also a problem that the cost increased.

Therefore, an object of the present invention is to provide a plate-shaped heater with a heater which can improve the thermal efficiency and can suppress the temperature rise of the box body forming the cooking chamber as much as possible. To provide a microwave.

[0006]

[Means for Solving the Problems]

 In the microwave oven with a heater of the present invention, a heater unit in which a flat-plate heater is covered with a radio wave reflection member is provided on the inner surface side of a box forming a cooking chamber with a gap between the heater and the box. It has a unique feature.

Further, it is more effective if the heater unit is provided in the recess formed in the top plate or the bottom plate of the box body so as to be substantially flush with the ceiling surface or the bottom surface of the cooking chamber. Is.

[0008]

[Action]

 According to the above means, since the heater unit having the flat heater is provided on the inner surface side of the box forming the cooking chamber, the heating unit can directly heat the cooking chamber. Therefore, the thermal efficiency is improved as compared with the case where the cooking chamber is heated through the box.

In this case, since the heater unit is configured by covering the flat-plate heater with the radio wave reflection member, there is no risk of being adversely affected by the radio waves during microwave oven cooking even when the heater unit is placed in the cooking chamber. ..

Moreover, since the heater unit is provided with a gap between the heater unit and the box body, it is possible to suppress heat transfer from the heater unit to the box body, and as a result, the temperature of the box body is reduced. The rise can be kept small.

Further, if the heater unit is provided so as to be substantially flush with the ceiling surface or the bottom surface of the cooking chamber, it is possible to improve the external appearance and the cleaning property.

[0012]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. First, the overall configuration of the microwave oven will be briefly described with reference to FIG. The main body 11 of the microwave oven is configured by providing an inner box 14, which is a box forming a heating chamber 13, in an outer box 12. An operation panel (not shown) is provided on the front surface of the main body 11, and a door 15 for opening and closing the heating chamber 13 is attached.

A magnetron (not shown), a drive circuit for the magnetron, and the like (not shown) are provided in a machine room provided adjacent to the heating chamber 13 in the outer box 12, and the heating chamber 13 is used when microwave oven cooking is performed. Microwaves are supplied into the interior of the kitchen for microwave heating. Further, as will be described later in detail, the inner box 14 is provided with two heater units 16 and 17, and when the heater cooking is performed, the cooked food in the cooking chamber 13 is generated by the heat generated by the heater units 16 and 17. It is supposed to be cooked.

Next, the inner box 14 and the heater units 16 and 17 will be described in detail with reference to FIGS. 1, 3 and 4. First, the inner box 14 is formed in a rectangular box shape with the front surface opened from the top plate portion 14a, the bottom plate portion 14b, the left and right side plate portions 14c (only one is shown), and the back plate portion 14d. Of these, the top plate portion 14a and the bottom plate portion 14b are provided with substantially rectangular recesses 18 and 19 for accommodating the heater units 16 and 17, respectively.

A through hole 14e is formed in the center of the bottom plate portion 14b, and a rotary shaft 20 for driving the turntable is provided so as to penetrate the through hole 14e. The rotating shaft 20 is rotated by a motor 21 provided on the inner bottom of the outer box 12. Further, as shown in FIG. 1, the bottom plate portion 14b is also provided with a through hole 14f for leading out a lead wire.

Now, regarding the heater units 16 and 17, the heater unit 17 on the side of the bottom plate portion 14b will be described as a representative. As shown in FIG. 4, the heater unit 17 has a rectangular plate shape having a circular hole 17a in the center thereof, and a flat plate heater 22 is housed in a case 23 as a radio wave reflection member in a substantially hermetically sealed state. Has been done.

As shown in FIG. 1, the flat heater 22 includes, for example, a thin core mica 24 wound with a heater wire 25 and two thin cover mica 26 for insulation. , 26 from above and below. As a whole, the flat plate heater 22 has a rectangular shape whose outer shape is one size smaller than the case 23, and has a hole part which is one size larger than the circular hole 17a in the center part. The core mica 24 and the cover mica 26, 26 have a thickness of 0.35 to 0.4 mm, for example, and the heating output of the flat heater 22 is 1200 W, for example.

The case 23 is configured to sandwich the flat heater 22 from above and below by a flat upper plate 27 and a shallow container-shaped lower plate 28. The upper plate 27 and the lower plate 28 are both made of, for example, a thin stainless steel plate having a radio wave reflecting function, and the case 23 includes the upper plate 27 and the lower plate 28 around the flat heater 22 and the holes. They are abutted at the inner peripheral portion of the portion, and the abutted portion is folded inward in a curl shape and caulked and joined. In this way, the flat heater 22 is covered with the case 23.

Further, on the lower surface side (lower surface plate 28) of the case 23, a plurality of mounting projections 23 a are formed by drawing, and a lead wire 25 a for energizing the heater wire 25 is provided. A burring hole 23b for leading out is formed. As shown in FIG. 1, the lead wire 25a is led out downward from the burring hole 23b while being protected by the insulator tube 29.

The heater unit 17 configured as described above is housed so as to fit snugly in the recess 19 formed in the bottom plate portion 14b, and is attached to the mounting projection 23a on the lower surface side of the bottom plate portion 14b. It is attached by tightening the screw 30 from the. As a result, the heater unit 17 is provided on the inner surface side of the inner box 14 with a gap corresponding to the height of the protruding portion 23a between the heater unit 17 and the bottom plate portion 14b.

At this time, as shown in FIGS. 1 and 3, the outer peripheral edge portion of the heater unit 17 is in contact with the inner peripheral edge portion of the concave portion 19 without any gap, and the upper surface of the heater unit 17 is bottom plate portion 14b. The surface of the cooking chamber 13 is substantially flush with the surrounding portion of the concave portion 19, and thus the bottom surface of the cooking chamber 13 has a flat state. At this time, the burring hole 23b is inserted into the through hole 14f of the bottom plate portion 14b, and the rotary shaft 20 penetrates the circular hole 17a of the heater unit 17.

Although detailed description is omitted, the heater unit 16 on the side of the top plate 14a has the same configuration as that of the heater unit 17 from which the circular hole 17a is removed. The ceiling surface of the cooking chamber 13 is provided on the inner surface side (inside the recess 18) with a gap corresponding to the height of the protrusion between the top plate portion 14a and the top surface portion 14a. There is.

Next, the operation of the above configuration will be described. When the heater cooking is executed, the heater units 16 and 17 (the flat heater 22) are energized. Then, the flat heater 22 generates heat, and this heat is transmitted to the food in the cooking chamber 13 through the upper plate 27 of the case 23 (the plate on the lower surface side of the case for the heater unit 16), and the food is added. Heat cooked.

In this case, since the heater units 16 and 17 are provided on the inner surface side of the inner box 14 that constitutes the cooking chamber 13, the cooking chamber 13 (cooked food) is not heated by the heater units 16 and 17. As a result, the food is heated directly, and thus efficient cooking is performed.

Further, the heat of the heater units 16 and 17 is also transferred to the lower plate 28 (the upper plate of the heater unit 16), but the heater units 16 and 17 have a slightly protruding portion 23a inside. Since it is only in contact with the box 14 and there is a gap between it and the inner box 14, the heat transfer from the heater units 16 and 17 to the inner box 14 can be suppressed to a small extent. That is, the temperature rise in is small.

While microwaves are supplied into the heating chamber 13 when microwave oven cooking is performed, since the heater units 16 and 17 are covered with the case 23 having a radio wave reflection function, the microwaves cause flat plates. The heater 22 is not adversely affected. In addition, water and the like are prevented from entering the heater units 16 and 17. Moreover, since the outer peripheral edge portions of the heater units 16 and 17 are in close contact with the inner peripheral edge portions of the concave portions 18 and 19, microwaves are transmitted from the through hole 14f for leading the lead wire of the inner box 14 to the outside of the cooking chamber 13 for example. It is also prevented from leaking to.

Further, particularly in this embodiment, since the heater units 16 and 17 are provided so as to be substantially flush with the ceiling surface and the bottom surface of the cooking chamber 13, the appearance is good and the bottom surface is For example, even if the juice of the cooked food is spilled, it can be easily cleaned.

As described above, according to the present embodiment, since the heater units 16 and 17 are provided on the inner surface side of the inner box 14 constituting the cooking chamber 13, the cooking chamber 13 (cooked food) is directly heated. can do. Therefore, as compared with the conventional structure in which the heat of the flat heater 4 is transferred into the cooking chamber 2 through the inner box 3, the heat dissipation is reduced, and the thermal efficiency can be greatly improved.

Further, since a gap is provided between the heater units 16 and 17 and the inner box 14, unlike the conventional one in which the temperature of the inner box 3 as a whole rises to a high temperature, the temperature of the inner box 14 rises. Can be kept low. As a result, it is not necessary to take strict measures such as heat shielding and heat insulation on the outer side of the inner box 14, and the cost can be reduced as compared with the conventional case.

Since the heater units 16 and 17 are configured by covering the flat heater 22 with the case 23 having a radio wave reflecting function, the flat heater 22 is provided on the inner surface side of the inner box 14. It is possible to prevent the occurrence of problems such as microwave and water intrusion that accompany it.

Further, particularly in the present embodiment, since the heater units 16 and 17 are provided so as to be substantially flush with the ceiling surface and the bottom surface of the cooking chamber 13, it is possible to improve the external appearance and the cleaning property. The effect can be obtained.

5 and 6 show another embodiment of the present invention, respectively. First, in the above-described embodiment, the outer peripheral edge of the heater unit 17 is brought into contact with the inner peripheral edge of the recess 19. However, in order to improve the reliability of sealing of that portion, as shown in FIG. For example, a ring-shaped sealing material 31 made of silicone rubber may be attached to the inner box side to seal between the two.

Further, in order to further reduce the radio wave leak from the through hole 14f (burring hole 23b) of the bottom plate portion 14b, a cylindrical choke cover 32 is provided on the back surface side of the bottom plate portion 14b as shown in FIG. It may be provided. In this case, it is effective to form the choke cover 32 with, for example, a height of 10 mm and a radius of 300 mm (1/4 of the microwave wavelength λ).

Besides, the present invention is not limited to the embodiments described above and shown in the drawings. For example, the heater unit may be provided only on one of the top plate portion 14a and the bottom plate portion 14b of the inner box 14. In addition, it is possible to achieve the intended purpose without necessarily providing the heater unit in the same plane, and it is possible to carry out appropriate modification within a range not departing from the gist.

[0035]

[Effect of the device]

 As is apparent from the above description, according to the microwave oven with a heater of the present invention, the heater unit in which the flat plate heater is covered with the radio wave reflection member is provided on the inner surface side of the box forming the cooking chamber. Since it is provided with a gap between it and the body, it is possible to improve the thermal efficiency of the flat plate heater when cooking with a heater, and also to raise the temperature of the box that constitutes the cooking chamber as much as possible. It has an excellent effect that it can be suppressed.

If the heater unit is provided in the recess formed in the top plate or the bottom plate of the box body so as to be substantially flush with the ceiling surface or the bottom surface of the control room, the above effect can be obtained. At the same time, it is possible to improve the appearance and the cleanability.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a heater unit showing an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional side view of an entire microwave oven with a heater.

FIG. 3 is a vertical sectional side view of the bottom portion of the cooking chamber.

FIG. 4 is a perspective view of a heater unit.

FIG. 5 is a vertical cross-sectional side view of essential parts showing another embodiment of the present invention.

FIG. 6 is a vertical cross-sectional side view of a main part showing another different embodiment.

FIG. 7 is a view corresponding to FIG. 2 showing a conventional example.

FIG. 8 is a vertical sectional side view of a main part showing a conventional example.

[Explanation of symbols]

In the drawing, 11 is a main body, 12 is an outer box, 13 is a cooking chamber, 14
Is an inner box (box), 16 and 17 are heater units,
Reference numeral 19 is a concave portion, 22 is a flat heater, 23 is a case (radio wave reflecting member), 27 is an upper plate, 28 is a lower plate, 31 is a sealing material, and 32 is a choke cover.

Claims (2)

[Scope of utility model registration request] 1. A flat heater for heating the cooking chamber is provided on at least one of a top plate and a bottom plate of a box forming the cooking chamber, wherein the flat heater is provided. A microwave oven with a heater, characterized in that a heater unit covered with a radio wave reflection member is provided on the inner surface side of the box with a gap between the box and the box. 2. The heater unit is provided in a recess formed in the top plate or the bottom plate of the box body so as to be substantially flush with the ceiling surface or the bottom surface of the cooking chamber. The microwave oven with a heater according to claim 1.